Audio spatial effects to model the movement of a sound-emitting video object as if the object were in the space in which the video is being displayed are typically provided using phased-array principles. The following patent documents, all owned by the present assignee and all incorporated herein by reference, outline techniques for producing audio spatial effects: U.S. Pat. Nos. 9,288,597, 9,288,597, 9,232,335; U.S. Patent Publications 20150208187, 20150215722, 20150215723, 2015033381; U.S. patent application Ser. Nos. 14/163,542, 14/968,349 (“gimbal 1”), Ser. No. 15/018,128, 15/019,111, 15/044,920, 15/044,981, 15/068,806 (“gimbal 2”), Ser. No. 15/072,098.
As an example, in the “gimbal” applications incorporated above, highly directional ultrasonic (US) speakers are mounted on a gimbal assembly to turn the gimbal assembly and thereby direct the sonic axes of selected speakers in desired elevation and azimuth (two dimensions), with audio spatial effects being emitted by the speakers. In this way, the perceived location of the source of the audio effects can be made to appear where desired, at least in the two dimensions defined by azimuth and elevation.